var sum = function (m, n) {
  if (arguments.length == 1) {
    return function (k) {
      return m + k
    }
  } else {
    return m + n
  }
}
console.log(sum(100)(200))
console.log(sum(100, 200))

var out = 5
inner = {
  out: 10,
  func: function () {
    var out = 15
    return this.out
  },
}
console.log((inner.func, inner.func)())
console.log(inner.func())
console.log(inner.func())
console.log((inner.func = inner.func)())

// let a = 10
// function f() {
//   console.log(a)
// }
// f()
